摘要
水钻切割法具有对围岩扰动小、断面成型质量高等特点,正逐步应用于城市电力隧道掘进施工。结合某电力隧道下穿双线既有轻轨隧道工程实例,采用有限元数值模拟,系统分析在不同围岩条件下水钻掘进引起既有隧道的变形规律及机理。通过现场监测数据验证理论模型的适用性,并提出既有隧道变形控制措施。计算结果表明:新建隧道与既有隧道净距为定值时,水钻切割对既有隧道影响因素包括围岩强度、掌子面距离、开挖速度及支护长度;在不同围岩强度下,水钻切割引起既有隧道的变形趋势具有一致性,但围岩强度越低,对既有隧道的影响越大。掌子面距既有隧道小于10 m时,既有隧道沉降速率增长较快,此时可通过控制开挖速度及支护长度减小既有隧道的变形。水钻切割引发既有隧道侧向变形较竖向变形小一个量级,施工中的监测及控制宜侧重于竖向变形。
The water drill method triggers small disturbance to surrounding rock and owns high quality of section forming,thus it is gradually applied to urban power tunnel excavation construction recently.Based on the background of a power tunnel under the two-line existing light rail tunnel project,the finite element numerical simulation is applied to systematically analyze the deformation rule and mechanism of the existing tunnel caused by the waterdrilling construction under different surrounding rock conditions.Then the applicability of the theoretical model is verified by in-situ monitoring data.Finally,control measures for existing tunnel deformation are proposed.The calculation results show that the factors affecting the existing tunnel by water drill include the strength of the surrounding rock,distance of the face,excavation speed and length of the support when the net distance between the new tunnel and the existing tunnel is fixed.Under different surrounding rock strengths,the deformation trend of the existing tunnel is similar under the water-drilling construction of the power tunnel,but the lower the surrounding rock strength,the greater the impact on deformation of the existing tunnel.When the face of the power tunnel is less than10 m from the existing tunnel,the settlement rate of the existing tunnel will increase rapidly.The deformation of the existing tunnel can be reduced by optimizing excavation speed and support length.The horizontal deformation of existing tunnels is smaller an order of magnitude than the vertical deformation,thus the monitoring and control action should focus on the vertical deformation.
作者
何钰江
汤丽
胡再江
宋璟
王丹妮
He Weijiang;Tang Li;Hu Zaijiang;Song Jing;Wang Danni(State Grid Chongqing Electric Power Company Construction Branch,Chongqing 617000,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2020年第S02期849-855,共7页
Chinese Journal of Underground Space and Engineering
关键词
水钻切割
电力隧道
轻轨隧道
数值计算
变形规律
施工措施
water drill
electric power tunnel
light rail tunnel
numerical calculation
deformation law
construction measure
作者简介
何钰江(1973—),男,重庆璧山人,硕士,主要从事电力系统、地下工程等领域的工作。E-mail:504075001@qq.com
